How fast to recirc during mash

I recently built a Brutus 10 type system and recirc during the mash. I"ve done about 6 brews on it. I've noticed the faster I recirculate (the more open the pump valve) the better I'm able to maintain a uniform and constant temperature but the grain bed gets compacted tighter. I typically stop stir it up and recirc a bit to reset the grain bed fairly slowly before starting the sparge. Is there any concern during the mash about how tight the grain bed gets during the mash? And how fast do you guys recirc? Assuming you all recirc whether its herms/rims, etc.

This is something I would like to know as well. I'm building a HERMS system for my MLT and I am really curious about the flow rate on the recirculating since an undisturbed grain bed seems to be ideal. Hopefully one of these geniuses gets on here soon and straightens us out!

First, I'm no genius so don't expect me to straighten you out

I start recirculating my mash as soon as I have my hands free from mashing in. I start VERY slowly for the first 10 minutest or so. I then gradually increase the flow. Since it's just recirculating, I can't really tell you how many GPM's or the exact flow rate. By the end of the mash, the flow is pretty fast, not full open, but pretty close. I have an in-line site glass and at higher flow rate is when the wort becomes very clear.

BTW... I have a RIMs system.

Ed

Thanks,

Do you stir up the bed at all after you start recirculating? Can you tell how tight the bed is? ooh that sounds dirty.

You're welcome.

I typically do not stir after I start re-circulating. I don't know how tight the grain is but have not had a problem.

Also, I fly sparge and use a false bottom.

Ed

1 gallon per minute works well in my experience. I get about a 1 degree per minute rise in the MLT and don't compact the grain bed and don't disturb it either. I have a separate HERMS. You can measure it with a stopwatch and a gallon container, just test it with water. I don't stir after initial dough-in.

HarkinBanks said:

1 gallon per minute works well in my experience. I get about a 1 degree per minute rise in the MLT and don't compact the grain bed and don't disturb it either. I have a separate HERMS. You can measure it with a stopwatch and a gallon container, just test it with water. I don't stir after initial dough-in.

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That's some good info. My setup will be with a keggle MLT with a false bottom and a HERMS system.